I have a W&S #2 and I need to thread the stem on an End Brush (see link)
to 1/4-20. The stem is about 1" long.

I guess I need a Geometric Die Head. I know little about them or other
methods. What size head should I be looking for? What inserts do I
want? Is there one on someone's shelf gathering dust?

I need to do about 200/hr. The threading will be done before the cup is
filled with wire.

http://www.ebay.com/itm/WEILER-10028...em33817d 2fa6

"Tom Gardner" Mars@Tacks wrote in message
...
I have a W&S #2 and I need to thread the stem on an End Brush (see link) to
1/4-20. The stem is about 1" long.

I guess I need a Geometric Die Head. I know little about them or other
methods. What size head should I be looking for? What inserts do I want?
Is there one on someone's shelf gathering dust?

I need to do about 200/hr. The threading will be done before the cup is
filled with wire.

http://www.ebay.com/itm/WEILER-10028...em33817d 2fa6


5/16 or 9/16 goemetric die head will do the job just fine. You want D-Style
self opening. Chasers are plentifull and cheap on ebay, new ones can be had
for 9.00 plus shipping. Do not buy used chasers, most have been sharpened
to thier limit and are worn out. You can expect to spend anywhere from
$25.00
to $100.00 for a die head. The chasers can be resharpened many times on
a surface grinder, geometric made several types of fixtures just for
sharpening.

You can download a old geomeric manual he

http://babel.hathitrust.org/cgi/pt?i...w=1up;seq=5 9

Be advised geometric is out of bussines. Repairs and support is
available from 3rd party vendors only.

Best Regards
Tom.
--
http://fija.org/

On 2013-10-15, Tom Gardner Mars@Tacks wrote:
I have a W&S #2 and I need to thread the stem on an End Brush (see link)
to 1/4-20. The stem is about 1" long.

I guess I need a Geometric Die Head. I know little about them or other
methods. What size head should I be looking for? What inserts do I
want? Is there one on someone's shelf gathering dust?

I need to do about 200/hr. The threading will be done before the cup is
filled with wire.

http://www.ebay.com/itm/WEILER-10028...em33817d 2fa6



If I had to do it at that scale (200/hr), I would look into brand new
stuff, well supported by dealers and manufacturer. Not into some old
stuff with hard to find parts.

i

On 2013-10-15, Tom Gardner Mars@Tacks wrote:
I have a W&S #2 and I need to thread the stem on an End Brush (see link)
to 1/4-20. The stem is about 1" long.

External thread, I presume.

I guess I need a Geometric Die Head. I know little about them or other
methods. What size head should I be looking for? What inserts do I
want? Is there one on someone's shelf gathering dust?

For 1/4" threads, if you aren't planning to go much larger, the
5/16" die head would be the best choice, but you could probably use up
to a 3/4" die head as long as you aren't going any smaller. A 1/2"
would be pretty reasonable if you can find them. Some sizes are hard to
find these days, and as I got all of mine from eBay auctions, I don't
know about commercial availability.

For a turret lathe (not to be confused with an automatic screw
machine, with which I have no real experience), you would likely need to
make an adaptor collar from the shank of the die head to the socket in
the turret. Mine has 1" turrets, and most 3/4" die heads come with 1"
shanks already.

The die head has "chasers" not "inserts". It looks like a 4-jaw
chuck, except that the faces of the jaws are formed to cut threads.

Depending on the material, you will want a different grind on
the chasers (rake and taper at the entry), and if you are going into
serious production, probably a second set of chasers (per thread you
want to cut), and a sharpening fixture for the chasers to be used on a
surface grinder.

The four jaws are closed to the cutting diameter by a lever,
usually hand operated on a simple turret lathe, or operaed by cams on
automatic screw machines, and fancy power-cycled turret lathes. When
the chasers contact the spinning workpiece, they start cutting the
threads, and pull the head and the ram of the turret in at the proper
speed, until you hit a stop set for that station on the turret. At this
point, the shank stops, but the chaser part of the hed is pulled a bit
forther in, releasing a lock which allows the hand lever to spring to
the "open" position, and the chasers to withdraw from contact with the
workpiece. This allows the turret to withdraw the Geometric die head
while the workpiece is still spinning. (There are also versions which
have a push to trip setup, if there is room for something for it to hit
in the lathe. Some can be converted fairly simply between the two
release techniques.

The force needed for that pull by the threads is the primary
limit on using smaller threads in larger die heads. The force required
scales with the heads.

Note that above I said that it was closed to the proper diameter
for the threads. Some have a small lever to switch between a roughing
and a finish pass, so you feed it on twice. These are useful if you
have a tougher material to machine. (Or, if you have stations to spare
on the turret, you can have one set to roughing, and another set to
finish to operate successively on the workpiece.)

I don't know what else you may be doing. I'll assume that the
workpiece will start out a bit oversized for the thread, so you will
want a roller box tool on the preceding station, to turn it down to the
proper diameter (just barely oversized) to accept the Geometric die
head. (You start off a little oversized, and you can check the settings
for pitch diameter by simply measuring over the completed thread,
because the thread form is complete.

Oh yes -- the chasers can have a shallow taper if you don't need
full threads up to a shoulder, or can have a much sharper taper if you
do need the full threads. When you buy the chasers, a good source will
ask you for the workpiece material and other things so they can supply
chasers sharpened to work optimally with that material.

The chasers are changed by pulling out a spring-loaded stop pin,
and allowing the closing lever to move past its normal stop, at which
point all four chasers can be slid out of their ways. (The ways and the
chasers are numbered, and *must* be installed in the proper places to
produce a proper thread.)

I need to do about 200/hr. The threading will be done before the cup is
filled with wire.

I think that it could handle that -- with a good fast chucking
system. An automatic screw machine could certainly do it.

I use mine (most often) on brass, involving turning down a bit,
knurling the part not turned down, threading 5/8-27 on the turned down
part, drilling the center, and tapping for a center mounting thread, and
then parting off -- and I have to stop and reverse the spindle for the
tapping at least, and I get about thirty to forty in a couple of hours,
with brass bar stock fed through a collet. You are just threading (as
far as you have said), so it mostly will be a function of how quickly
you can chuck and unchuck the workpieces.

http://www.ebay.com/itm/WEILER-10028...em33817d 2fa6

Looking at that, I'm assuming that the major turning is being
done on another machine. A proper collet to accept the cup (ideally
with a stop to keep the depth consistent) would work well -- but you
would have to stop the spindle for the change of workpiece.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Mon, 14 Oct 2013 20:25:32 -0700, "azotic"
wrote:




"Tom Gardner" Mars@Tacks wrote in message
m...
I have a W&S #2 and I need to thread the stem on an End Brush (see link) to
1/4-20. The stem is about 1" long.

I guess I need a Geometric Die Head. I know little about them or other
methods. What size head should I be looking for? What inserts do I want?
Is there one on someone's shelf gathering dust?

I need to do about 200/hr. The threading will be done before the cup is
filled with wire.

http://www.ebay.com/itm/WEILER-10028...em33817d 2fa6


5/16 or 9/16 goemetric die head will do the job just fine. You want D-Style
self opening. Chasers are plentifull and cheap on ebay, new ones can be had
for 9.00 plus shipping. Do not buy used chasers, most have been sharpened
to thier limit and are worn out. You can expect to spend anywhere from
$25.00
to $100.00 for a die head. The chasers can be resharpened many times on
a surface grinder, geometric made several types of fixtures just for
sharpening.

You can download a old geomeric manual he

http://babel.hathitrust.org/cgi/pt?i...w=1up;seq=5 9

Be advised geometric is out of bussines. Repairs and support is
available from 3rd party vendors only.

Best Regards
Tom.

Another Excellent die head is "H&G"
Can be had cheaper than Geometic and brand new dies are still somewhat
available.

Gunner

--
""Almost all liberal behavioral tropes track the impotent rage of small
children. Thus, for example, there is also the popular tactic of
repeating some stupid, meaningless phrase a billion times" Arms for
hostages, arms for hostages, arms for hostages, it's just about sex, just
about sex, just about sex, dumb,dumb, money in politics,money in
politics, Enron, Enron, Enron. Nothing repeated with mind-numbing
frequency in all major news outlets will not be believed by some members
of the populace. It is the permanence of evil; you can't stop it." (Ann
Coulter)

On 15 Oct 2013 05:05:25 GMT, "DoN. Nichols"
wrote:

On 2013-10-15, Tom Gardner Mars@Tacks wrote:
I have a W&S #2 and I need to thread the stem on an End Brush (see link)
to 1/4-20. The stem is about 1" long.

Tommy..contact Leigh at MarMachine in Costa Mesa California. He had a
literal ****load of H&G chasers as well as Geometric in all sizes.
Most of the chasers were NOS

Tell him Gunner said to give you a good price.

Gunner

--
""Almost all liberal behavioral tropes track the impotent rage of small
children. Thus, for example, there is also the popular tactic of
repeating some stupid, meaningless phrase a billion times" Arms for
hostages, arms for hostages, arms for hostages, it's just about sex, just
about sex, just about sex, dumb,dumb, money in politics,money in
politics, Enron, Enron, Enron. Nothing repeated with mind-numbing
frequency in all major news outlets will not be believed by some members
of the populace. It is the permanence of evil; you can't stop it." (Ann
Coulter)